Sound Absorption by Insulating Firebricks

摘要

Drilling non-thru holes on the surface of IFB with high permeability, we can get practical sound absorption at 500 approx 1250Hz. By adopting thru holes and air gap behind IFB, we can get practical sound absorption at 100 approx 500Hz. Both of these absorption may come from resonance and the resonant frequency is controlled by the configuration of holes and air gap.